Scott Edelman's post about twittering at ReaderCon reminded me of something I wanted to make clear. At the panel on online vs print, people were talking about the "things you can do online that you can't do in print", bringing up hypertext links and hovering over a word to make something pop up, and thus missing th point completely.
The reason online publishing is better than print publishing is that I can fit millions of pages of online content in my pocket. It's the instant availability and portability of e-content that is e-publishing's "killer app". Everything else is dressing.